My feeling here is that it's just like when someone in your family buys a particular make/model of car, you start noticing the same car on the road and are surprised that you never noticed how many of them there are.

That same ad for a set of Bose headphones might show up in your feed once a week, but one of those days you just happen to have a conversation about headphones with a friend, and it feels weird.

The paranoia in me sometimes wants to believe that my phone is listening to me all the time and is extracting ad keywords from everything I say, but I have a hard time figuring out how it would work.

Uploading voice clips, even using a good compressor like Opus, would still be noticeable. Maybe not by me, personally, but someone would have noticed that by now. Doing on-device voice recognition is possible (uploads of compressed text might not be noticeable), but my intuition is that would be a huge drain on the battery if it was running all day, processing everything it hears.

But who knows. Maybe it is possible, and there's a novel, but secret technology that enables it. It's a little far-fetched, though, I think.